Quick Summary
The FOMTOR 31.8 Mountain Bike Stem is a short bicycle stem for 31.8 mm handlebars and a 28.6 mm steer tube. It is described as a 45 mm stem with a 130 g weight, making the fit checks the main point before choosing an offer.
The stem is described as suitable for road bikes, fixed gear bicycles, mountain bikes, downhill bikes, track bikes, MTB, BMX and DH bikes. It uses a four-bolt bar clamp and is made from CNC machined 6061 T6 aluminium alloy.
Key Details
| Detail | Verified information and buyer relevance |
|---|---|
| Brand | FOMTOR. Useful for identifying the exact stem range. |
| Product type | Bicycle stem. Check handlebar and steer tube fit before choosing. |
| Handlebar diameter | 31.8 mm. This must match the handlebar size. |
| Steer tube diameter | 28.6 mm. This must match the fork steerer size. |
| Length | 45 mm, measured as the centre distance of the two holes. This affects front-end reach. |
| Weight | 130 g. Useful when comparing stem weight with other options. |
| Clamp design | Four-bolt bar clamp. Compare this with the clamp style you want. |
| Material | CNC machined 6061 T6 aluminium alloy. Material choice is part of the buying decision for many riders. |
What to Compare Before Buying
- Handlebar size: This stem is for 31.8 mm handlebars, so the bar diameter needs to match exactly.
- Steer tube size: The stated 28.6 mm steer tube diameter needs to suit the fork steerer on the bike.
- Reach: The 45 mm length is the main fit and riding-position figure to compare if you want a shorter stem.
- Clamp style: The four-bolt bar clamp is a useful check if you prefer a particular handlebar clamp layout.
- Bike type: The stem is described for several bike styles, so confirm it suits the exact build you are working on.
Who This Product May Suit
This stem may suit riders replacing or upgrading a bike stem where the handlebar is 31.8 mm and the steer tube is 28.6 mm. It is also relevant for builds where a 45 mm stem length is the right reach figure to compare.
The four-bolt clamp and short stem format make it a clear fit-check item for mountain bikes, road bikes, BMX, downhill bikes and similar bicycles listed with those sizes.
Before You Decide
Confirm the 31.8 mm handlebar size and 28.6 mm steer tube size before choosing an offer. Check that 45 mm is the stem length you want for the bike setup. If the clamp layout matters, review the four-bolt design against your current build.
